ConcepTest: Calculating Rock Age from Parent Radioactive Isotope
This material was originally created for
Starting Point:Introductory Geology and is replicated here as part of the SERC Pedagogic Service.
Initial Publication Date: May 8, 2006
Question:
A radioactive (parent) isotope of element X is discovered in different amounts in four rocks (A, B, C, D) of the same composition. Which rock has the oldest calculated age?
a. 15% of element X remains in Rock A
b. 57% of element X remains in Rock B
c. 28% of element X remains in Rock C
d. 75% of element X remains in Rock D
a. 15% of element X remains in Rock A
b. 57% of element X remains in Rock B
c. 28% of element X remains in Rock C
d. 75% of element X remains in Rock D
Student Responses:
No data yet. The correct response is d.
If you would like to help acquire more Before and After statistics for this example, please contact the authors (see link at top of page).
References and Notes:
The use of ConcepTests and Peer Instruction is discussed in detail on the ConcepTest page.
McConnell, D.A., Steer, D.N. and Owens, K.A., 2003, Assessment and Active Learning Strategies for Introductory Geology Courses, Journal of Geoscience Education, 51(2), 205-216.
McConnell, D.A., Steer et al., 2006, Using Conceptests to Assess and Improve Student Conceptual Understanding in Introductory Courses, Journal of Geoscience Education, (54(1), 61-68.